A vehicle seat typically includes foam that is compressible to conform to the contours of an occupant so that the occupant is comfortably supported. A flexible covering, such as fabric, leather, or vinyl, covers the foam and forms the outer surface of the seat. A vehicle seat is typically characterized by a lower seat portion and a seatback portion. The lower seat portion defines a generally horizontal surface to support an occupant, and the seatback portion defines a generally vertical surface to support the back of an occupant.
Certain prior art vehicle seats include pneumatic systems to control the firmness of the seat. The pneumatic systems include a bladder within the seat that is selectively pressurized with air to control the firmness of the seat. A system of pumps and valves is employed to pressurize and depressurize the bladder.